Earlier quoted context omitted.
EC2 migrated off Xen around ten years ago. Only really old instances should be using Xen or Xen emulation.
I'm puzzled by your comment. On an EC2 instance of AL2023 deployed on us-east-1 region this is the output of hostnamectl: [ec2-user][~]$ hostnamectl Static hostname: ip-x-x-x-x.ec2.internal Icon name: computer-vm Chassis: vm Machine ID: ec2d54f27fc534ea74980638ccc33d96 Boot ID: 6caf18b7ed3647819c1985c11f128142 Virtualization: xen Operating System: Amazon Linux 2023.5.20240903 CPE OS Name: cpe:2.3:o:amazon:amazon_linu…
https://www.theregister.com/2017/11/07/aws_writes_new_kvm_ba...
It could be that it's not all over and tied to specific machine types still, or there's something they've done to make it report to the guest still that it's xen based for some compatibility reasons.